Reverse Engineering the World’s Most Advanced EV & ESS Li-Ion Battery Systems
We don’t just tear down devices—we decode them
Battery Pack of an EV with BMS controller
In today’s Electric Vehicle (EV) and grid-storage (also known as Energy Storage System, ESS) landscape, the Battery Management System (BMS) is no longer a simple safety controller. It is the defining intelligence layer that determines safety, performance, reliability, and competitive advantage. While whitepapers and datasheets describe only the surface, the real innovation lies deep inside the production hardware and the embedded firmware. For details of the underlying principles of BMS architecture and associated reverse engineering please see our white paper on The Critical Role of Battery Management Systems in Electric Vehicles and Energy Storage.
This is where GHB Intellect’s effective reverse-engineering (RE) practice delivers unmatched value. By dissecting real EV and ESS systems at the hardware, circuit, and firmware levels, we uncover how industry leaders actually design, implement, and protect their most advanced BMS technologies.
Our BMS reverse engineering supports OEMs, suppliers, investors, and litigators in their quest for:
- Competitive and technology benchmarking
- Intellectual property protection
- Evidence-of-Use (EoU) detection
- Safety and reliability evaluation
- Innovation scouting
- Battery model development and algorithm validation
Reverse engineering provides insights that cannot be obtained through documentation alone. And, GHB Intellect is one of the few organizations globally that is capable of performing this level of analysis comprehensively (including BMS electronics, battery pack mechanics, and battery cell chemistry). Here we will only focus on BMS electronics. For Battery cell chemistry analysis, please see Lithium-Ion Battery Innovations.
1. A Four-Layer Framework for BMS Reverse Engineering
Our teardown and RE workflow combines advanced engineering, laboratory analysis, and real-world validation to produce a complete map of how a Battery Management System (BMS) is architected.
1.1 Physical Teardown & Component Identification
The process begins with systematic disassembly of the battery pack:
- Pack opening and high-voltage isolation
- Module and cell extraction
- BMS controller removal
- Detailed imaging and component cataloging
- Identification of sensors, fuses, isolation devices, gate drivers, ASICs, and microcontrollers
Figure 2 shows an example of a battery pack teardown and extraction of master and slave BMS boards.
Figure 2: Example of teardown of an EV battery pack, a) battery pack, b) battery module, c) BMS master board and d) BMS Slave board
This phase reveals the OEM’s choices in safety architecture, sensing topology, power distribution, and internal redundancy.
As shown in Figure 3, our teardown workflow follows a disciplined, multi-stage process that reveals the OEM’s design intent at every level—pack, module, board, and component.
Figure 3: Teardown Workflow for BMS Hardware Analysis
1.2 Circuit-Level Reverse Engineering
Once the hardware is exposed, our engineers reconstruct the full electrical architecture of the BMS:
- Protection and contactor drive circuits
- Current and voltage sensing front-ends
- Passive/active balancing networks
- Isolation monitors and redundant safety channels
- High-side/low-side power management
- CAN/LIN communication and wake-up circuitry
By reconstructing the full schematics and identifying every circuit connection and functional block, we reveal the OEM’s design philosophy, including strategies for noise immunity, fault tolerance, accuracy, balancing speed, and safety margins.
Figure 4 illustrates our end-to-end workflow for circuit reverse engineering, showing how we translate a complex, multi-layer PCB into a complete and interpretable electrical schematic. By combining delayering, CT-scan analysis, and component re-annotation (assigning new, consistent reference designators when original markings are missing or unclear) with detailed tracing of every net (that is, each electrical connection linking components across layers) we uncover the design principles that shape the OEM’s BMS architecture.
Figure 4: Circuit Reverse Engineering Flow
1.3 CT-Scanning & PCB Delayering
Modern BMS PCBs commonly feature:
- 4–12 layers
- Buried vias
- Segmented ground domains
- Dense analog and high-voltage routing
To reveal the hidden structure, GHB Intellect uses:
- 2D X-ray imaging
- High-resolution 3D CT scanning
- Mechanical and/or chemical delayering
Figure 5 shows an example of a 2D CT-scan image acquired from a master BMS board. These scans allow us to non-destructively visualize internal copper planes, vias, and high-density routing patterns before physical delayering begins. This imaging step provides critical insight into the board’s internal architecture and guides the subsequent layer-by-layer analysis.
Figure 5: Example of 2D image obtained by CT-Scan of a master BMS
These analyses allow us to reconstruct every copper layer, inner-layer via, and trace pat, producing a complete visual and electrical representation of the board.
Figure 6 illustrates our CT-scanning and PCB delayering pipeline, which enables us to visualize and extract the internal structure of multi-layer BMS circuit boards. By combining 2D X-ray, high-resolution CT imaging, and mechanical or chemical layer removal, we expose buried copper layers, vias, ground domains, and routing paths that cannot be observed from the surface. This information feeds directly into accurate net tracing and schematic reconstruction.
Figure 6: CT-Scan and PCB Delayering Pipeline
1.4 Firmware Reverse Engineering: Exposing the Algorithmic Core
The heart of modern BMS intelligence is its firmware. It contains:
- SOC/SOH/SOP estimation algorithms
- Kalman filtering and adaptive observers
- Fast-charging logic and derating behavior
- Thermal-management decision layers
- Fault detection, anomaly detection, and isolation routines
- Secure boot, OTA update logic, and diagnostic handlers
GHB Intellect is able to perform:
- Firmware extraction (JTAG/SWD/BDM, diagnostic ports, chip-level methods)
- Binary disassembly and symbol analysis
- State-machine reconstruction
- Correlation with HIL (hardware-in-the-loop) testing
- Identification of algorithmic implementation of ECM, EM, EIS, and ML-based models
This allows us to map the OEM’s complete algorithmic strategy—from sensing and filtering to safety enforcement and performance optimization.
Figure 7 presents the workflow used for firmware reverse engineering, detailing how we extract, decode, and interpret the embedded algorithms that govern BMS behavior. This process includes firmware extraction, binary analysis, state-machine reconstruction, and correlation with hardware-in-the-loop testing, allowing us to uncover the OEM’s strategies for estimation, protection, diagnostics, and system-level decision-making.
Figure 7: Firmware Reverse Engineering Flow
2.Why BMS Reverse Engineering Matters More Than Ever
2.1 Competitive Benchmarking
OEMs invest heavily in BMS design. Reverse engineering (RE) reveals:
- How top EV makers balance safety vs. performance
- Proprietary balancing, sensing, and protection strategies
- The evolution of algorithms across generations
This intelligence supports strategic planning, R&D road-mapping, and technology gap analysis.
2.2 Patent Protection & Evidence-of-Use
GHB Intellect routinely supports patent litigation, licensing, and portfolio evaluation. Our RE work identifies:
- Circuit-level implementation of claimed inventions
- Firmware routines matching patented estimation logic
- System-level behaviors corresponding to patented methods
- Novel techniques worthy of new patents
This is indispensable for legal teams, patent owners, and licensors.
2.3 Safety and System Assurance
Understanding how a BMS detects faults, handles wake-up and shutdown, manages contactors, and filters sensor noise is crucial for verifying:
- Compliance with ISO 26262
- Robustness under abnormal conditions
- Redundancy and fail-safe mechanisms
2.4 Technology Scouting & M&A Due Diligence
For investors, suppliers, or OEMs evaluating partnerships or acquisitions, RE provides the clearest possible insight into the maturity and competitiveness of a company’s BMS technology.
3.Turning Reverse Engineering into Actionable Intelligence
GHB Intellect RE effort is designed to enable:
- Full schematic and PCB reconstructions
- Algorithm maps and firmware documentation
- Block-level architecture identification
- Identification of IP and competitive differentiators
- Benchmarking EV/ESS platforms
- Actionable insights for R&D, legal, and business teams
These deliverables are used by:
- Automotive OEMs
- Battery developers
- BMS suppliers
- Legal teams
- Investors and analysts
- Energy storage integrators
Our multidisciplinary team—battery scientists, circuit designers, firmware analysts, and IP strategists—ensures that every layer of the system is interpreted correctly and placed in context.
Why Choose GHB Intellect?
GHB Intellect is uniquely positioned to investigate battery management systems (BMS) because we combine:
- Deep electrochemical expertise (NMC 811, LFP, LNMO, Si-blends) through our Battery Cell Characterization product
- Advanced materials analysis
- BMS architecture & control knowledge
- Circuit and PCB reconstruction capabilities
- Firmware reverse-engineering specialties
- Extensive expertise in patents, IP, and litigation support
These multi-disciplinary expertise and capabilities are necessary to not only document what exists, but also explain why it was designed that way, how it compares to the competition, and where opportunities exist for improvement or innovation.
If you’re developing next-generation EVs, battery modules, or energy-storage products, understanding real-world BMS design is essential. GHB Intellect can help you uncover the architecture, circuitry, algorithms, and IP that define market-leading systems. Contact us to learn how our BMS reverse engineering, technical intelligence, and advanced battery analysis can accelerate your R&D, strengthen your IP position, and give you a competitive edge. Connect with our team today to start your reverse-engineering engagement.
About GHB Intellect
GHB Intellect is a specialized technology consulting and intellectual property services firm providing advanced technical analysis, engineering/reverse engineering, and expert evaluations across a wide range of industries. Our battery characterization team combines deep expertise in electrochemistry, materials science, microscopy, spectroscopy, and failure analysis to deliver actionable insights for product development, competitive benchmarking, M&A due diligence, and IP litigation.
With world-class laboratories, cutting-edge instrumentation, and multi-disciplinary experts, GHB Intellect transforms complex technical data into clear, defensible, and decision-driving intelligence.